If you have been reading about reconstitution and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-03-11. Numbers and descriptions here follow the published literature rather than marketing material.
Thymosin alpha-1 is a synthetic peptide of 28 amino acid residues that corresponds to a naturally occurring fragment first isolated from thymus tissue. Its chain is acetylated at the amino terminus, a modification that shields the peptide from rapid cleavage by aminopeptidases. The molecule carries a net negative charge at physiological pH and dissolves freely in water. Researchers classify it as an immune-modulating agent rather than a classical hormone, because it acts on several cell types of both the innate and the adaptive immune system.
The peptide was identified during work in the 1970s on thymosin fraction 5, a partially purified extract of calf thymus. Investigators separated that mixture and characterized individual components, one of which they named thymosin alpha-1. The same compound later received the international nonproprietary name thymalfasin. Commercial material is produced by solid-phase peptide synthesis rather than by extraction, so synthetic and natural forms share an identical sequence. Naming conventions vary across the literature, and readers should distinguish the alpha-1 peptide from other thymosins that have unrelated sequences and functions.
Thymosin beta-4 is a separate 43-residue peptide that binds actin and participates in cell migration; it shares no sequence similarity with thymosin alpha-1 despite the common family name. Other preparative materials, such as thymosin fraction 5 and thymopoietin, contain distinct mixtures or peptides. The shared thymosin label reflects the tissue of origin used in early purification, not a common structural core. Treating these molecules as interchangeable is a frequent source of confusion in laboratory reports and in popular summaries alike.
Thymosin alpha-1 is a short peptide of 28 amino acid residues first described in the 1970s as a component of thymic extracts. Its N-terminal residue carries an acetyl group, and the sequence is highly conserved across mammalian species. The peptide is not encoded as a standalone gene product; it is released by proteolytic cleavage from the N-terminus of prothymosin alpha, a larger acidic nuclear protein. That precursor relationship places it within a broader family of thymic and immune-associated peptides that have been studied for decades.
The activity of this peptide is generally described as immunomodulatory rather than directly antimicrobial. Experimental work links it to signaling through certain Toll-like receptors on dendritic cells and to downstream maturation of antigen-presenting cells. Reported effects include expansion of T cell subsets, shifts in cytokine profiles, and increased natural killer cell activity. These observations come largely from cell culture and animal models, and the precise receptor-level events in humans remain incompletely characterized.
The compound has been investigated as an adjunct in chronic viral hepatitis and as a vaccine adjuvant, with results that vary by study design and population. Regulators in some countries have approved a synthetic form for specific indications, while other agencies have not. Whether the peptide produces consistent clinical benefit across diverse patient groups is still an open question, and many trials have been small. Its status is therefore best described as investigational in many contexts and established only narrowly.
| Property | Value | Notes |
|---|---|---|
| Molecular mass | About 3.1 kDa | 28 residues, N-terminally acetylated |
| Appearance | White to off-white powder | Lyophilized solid |
| Solubility | Freely soluble in water | Also soluble in aqueous buffers |
| Storage temperature | 2 to 8 °C | Protect from light and moisture |
| Common synonyms | Thymalfasin; Tα1 | Same peptide sequence |
Thymosin alpha 1 was identified in 1977 as a component of thymosin fraction 5, a heterogeneous preparation used in early studies of thymic function. Investigators purified the active material and determined its amino acid sequence, which enabled chemical synthesis. Work in the following decades concentrated on T-cell maturation and immune reconstitution in animals and small human cohorts. Early preparations varied in composition, so results from that period are difficult to compare with studies using defined synthetic peptide.
Clinical research has examined the peptide in chronic hepatitis B and C, as a vaccine adjuvant, and in sepsis and oncology settings. Findings across trials are mixed; some report changes in selected immune markers, while others find no clear clinical benefit. Many studies are small and define outcomes differently, which limits comparison. Regulatory approval is confined to a few countries, and the compound is not an approved drug in the United States or most of Europe.
Thymosin alpha-1 is supplied as a lyophilized powder in most research settings. The solid dissolves readily in water and in common aqueous buffers, and it is typically reconstituted shortly before use. Solutions are clear and colourless at ordinary working concentrations. Because the peptide is hygroscopic, weighing and reconstitution are usually performed with minimal exposure to ambient air. Aliquots are prepared to avoid repeated freeze-thaw cycles, and working solutions are kept cold.
Long-term storage is generally at minus twenty degrees Celsius or colder, preferably desiccated and protected from light. Lyophilized material is more stable than reconstituted solution, which degrades faster at room temperature. Stability depends on pH, ionic strength, and the presence of oxidising agents. Published stability data for the peptide are limited, so storage claims in catalogues should be treated as general guidance rather than measured guarantees. Freeze-thaw cycles are kept to a minimum.
=== EC 1.2.99: With unknown physiological acceptors === EC 1.2.99.1: Now EC 1.17.99.4, uracil/thymine dehydrogenase EC 1.2.99.2: Now EC 1.2.7.4, carbon-monoxide dehydrogenase (ferredoxin) EC 1.2.99.3: Now EC 1.2.5.2, aldehyde dehydrogenase (quinone) EC 1.2.99.4: Now EC 1.2.98.1, formaldehyde dismutase EC 1.2.99.5: Now EC 1.2.7.12, formylmethanofuran dehydrogenase EC 1.2.99.6: carboxylate reductase EC 1.2.99.7: aldehyde dehydrogenase (FAD-independent) EC 1.2.99.8: glyceraldehyde dehydrogenase (FAD-containing) EC 1.2.99.9: Now EC 1.17.98.3, formate dehydrogenase (coenzyme F420) EC 1.2.99.10: 4,4′-diapolycopenoate synthase
Christopher Cantelmo (June 19, 1962 – November 24, 2019) was an American biochemist. In 2019 he became known on Reddit under the username u/ChrisCGC for spending large sums on awards while promoting the use of DMT. The online activity around his posts was sometimes referred to as Cantelmoism.
== Honours and awards == Doctorate honoris causa, Politics, Moscow State Institute of International Relations, Moscow, Russian Federation. Doctorate honoris causa, Duncan of Jordanstone College, University of Dundee, Scotland, United Kingdom. Ehrenbürgerschaft, Honorary Citizenship, awarded by the Christian Albrecht University, Kiel, Germany. Орден Дружбы, Order of Friendship presented by President Vladimir Putin of the Russian Federation. Нагрудный знак "Почетному полярнику", Honorary Polar Explorer Medal, Aspol, Moscow, Russian Federation. མངའ་བདག་དཔལ་གྱི་འཁོར་ལོ། Nga Dap Pel Gi Khorlo, The Order of the Druk Gyalpo, presented by King Jigme Khesar Namgyel Wangchuck of Bhutan. Silver Medal of Russian Geographic Society, awarded by the RGS, Russian Federation. Medal of Honour, granted by the Granada Dance and Music International Festival, Spain. Knight of the Order of St John by Queen Elizabeth II. The winner of the national award "Crystal Compass". (Russia)
Sources: en.wikipedia.org
She added that the clitoris "extends away from the body in a sleek and slender arc, measuring, on average, over 17 cm from root to tip. Just like a penis, [it] is fully erectile, raising its head in hyena greeting ceremonies, social displays, games of rough and tumble or when sniffing out peers".
The protein tropomyosin covers the myosin-binding sites of the actin molecules in the muscle cell. For a muscle cell to contract, tropomyosin must be moved to uncover the binding sites on the actin. Calcium ions bind with troponin C molecules (which are dispersed throughout the tropomyosin protein) and alter the structure of the tropomyosin, forcing it to reveal the cross-bridge binding site on the actin. The concentration of calcium within muscle cells is controlled by the sarcoplasmic reticulum, a unique form of endoplasmic reticulum in the sarcoplasm. Muscle cells are stimulated when a motor neuron releases the neurotransmitter acetylcholine, which travels across the neuromuscular junction (the synapse between the terminal button of the neuron and the muscle cell). Acetylcholine binds to a post-synaptic nicotinic acetylcholine receptor. A change in the receptor conformation allows an influx of sodium ions and initiation of a post-synaptic action potential. The action potential then travels along T-tubules (transverse tubules) until it reaches the sarcoplasmic reticulum. Here, the depolarized membrane activates voltage-gated L-type calcium channels, present in the plasma membrane. The L-type calcium channels are in close association with ryanodine receptors present on the sarcoplasmic reticulum. The inward flow of calcium from the L-type calcium channels activates ryanodine receptors to release calcium ions from the sarcoplasmic reticulum. This mechanism is called calcium-induced calcium release (CICR).
== Grand Mufti of Saudi Arabia == On 22 October 2025, under recommendation by Crown Prince Muhammad bin Salman, King Salman appointed al-Fawzan as Grand Mufti of Saudi Arabia, succeeding Abdulaziz Al al-Sheikh.
Sources: en.wikipedia.org
It is a 28-residue synthetic peptide studied as an immune-modulating agent and approved as a drug in some countries. The sequence matches a naturally occurring fragment isolated from thymus tissue. It is not a hormone in the endocrine sense.
The name traces back to thymosin fraction 5, a crude thymus extract examined in the 1970s. Individual peptides in that mixture were labeled with Greek letters, and alpha-1 was one of them. The international nonproprietary name thymalfasin was assigned later.
No. Thymosin beta-4 contains 43 residues and binds actin, while thymosin alpha-1 contains 28 residues and acts on immune cells. The two sit in a historical naming group but share no sequence similarity, and they are not substitutes for one another.
It is usually classified as an immunomodulatory peptide rather than a classical hormone. It derives from the larger protein prothymosin alpha and acts mainly on immune cells. The thymosin label covers a group of distinct peptides, so the naming can be misleading.